LACK OF CORRELATION BETWEEN TBARS PRODUCTION AND PUFA DEGRADATION DURING INCUBATION OF MEMBRANE ERYTHROCYTES IN AN OH-CENTER-DOT (FE2+ H2O2) GENERATOR SYSTEM/

We investigated the effects of an OH. (Fe2+/H2O2) generator system on erythrocyte membrane, particularly the time-course of lipid peroxidati on as estimated by measurement of conjugated dienes, thiobarbituric re active substances (TEARS), lipofuscin-like pigments, and alpha-tocophe rol. Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (20:4 omega 6) and docosahexenoic acid (22:6 omega 3), were also measu red. Erythrocyte membranes were suspended in phosphate buffer containi ng Fe2+ (200 mu M) and H2O2 (1.42 mM), and incubated in a shaking wate r bath at 37 degrees C. Initially, there was an increase in TEARS and lipofuscin-like pigments, two well-known end products of PUFA oxidativ e degradation, whereas PUFAs remained unchanged (incubation time: 1 h) . After two or more hours of incubation, marked lipid peroxidation was noted, with the appearance of conjugated dienes and a decrease of PUF As, indicating that Lipid peroxidation had occurred after a lag phase during which TEARS were not produced from PUFAs. This suggests that an other OH. target was involved.